Apparatus for rocking a photographic tray



Nov. 18, 1969 1 H. BISHOP APPARATUS FOR ROCKING A PHOTOGRAPHIG TRAYFiled Aug. 2, 1967 INVENTOR Lewis H. Bishop United States Patent O` i3,478,666 APPARATUS FOR RO'lIZG A PHOTOGRAPHIC Lewis H. Bishop, SanCarlos, Calif., assignor to Pierce Specialized Equipment Company, SanCarlos, Calif., a corporation of California Filed Aug. 2, 1967, Ser. No.657,967 Int. Cl. G03d 3/04 U.S. Cl. 95-99 6 Claims ABSTRACT oFTHE'DIscLosURE A tray rocker including a housing having outwardlyextending tabs for supporting a platform for four way rocking motionabout intersecting axes lying in common plane. Holes in the tabs receiveguide pins associated with the platform to define the axes. A pluralityof cams are attached to the lower surface of the platform and areengaged sequentially by a rotating rotor arm having a cam drive bearingat its outer end.

Background of the invention This invention relates to apparatus forrocking a photographic tray and in particular to such apparatus by whicha photographic tray is sequentially rocked to provide agitation ofliquid contained in the tray.

In the development and processing of photographic films, it is commonpractice to agitate the developer in different directions by smoothlyraising and lowering the sides of the tray so that the developer flowsto the opposite side of the tray and returns, washing fresh solutionover the film, It is recommended practice to carry out the agitation ina sequence wherein adjacent sides or corners of the tray aresuccessively raised and lowered to form an agitation cycle. If performedby hand, this agitation cycle becomes quite'tedious. Previouslyavailable apparatus for performing this operation has been undulycumbersome, complex, and expensive, and has required special powersources.

In general, it is an object of the present invention to provideapparatus for rocking a photographic tray which will overcome the abovementioned limitations and disadvantages, and which derives therecommended sequential rocking motion from a simple rotary motion.

Another object of the invention is to provide an apparatus of the abovecharacter which is particularly simple and reliable, requiring a minimumof maintenance, and which is adapted to be operated from commonlyavailable electrical power.

In general, the above objects are achieved Iby providing a platform forcarrying a photographic tray containing the solution to be agitated.Means are provided for supporting the platform in a substantiallyhorizontal plane or position while permitting it to be pivoted aboutintersecting axes lying in the horizontal plane. The platform isprovided with means defining a cam track having varying levels withrespect to the platform. Rotatable means is positioned for travel underthe platform and adapted to sequentially engage portions of the camtrack during the agitation cycle or interval so that the platform andtray are sequentially raised as the rotatable means travels about saidtrack. These and other features and objects of the invention will becomeapparent from the following description and the accompanying drawings.

according to the invention.

FIGURE 2 is a side elevational view of the apparatus 3,476,666 PatentedNov. 18, 1969 rice of FIGURE 1 with portions broken away to revealinternal mechanical features.

FIGURE 3 is a top plan view, partially broken away, of the apparatus ofFIGURE 1.

FIGURE 4 is a sectional view taken along the lines 4-4 of FIGURE 3.

Detailed description As shown in the figures, the apparatus of theinvention includes a housing 10 which supports a platform 12 forcarrying a tray 14 containing a photographic solution 16. Housing 10consists of a box-like structure having interconnected side walls 17a,b, c, d with sufiicient depth to accommodate the mechanical elements ofthe apparatus, and to provide a watertight compartment for the same.Angles are fastened to the side walls 17 and provide outwardly extendingtabs 18a, b, c, d which are located at the corners of a rectangle lyingin a substantially horizontal plane above the housing 10. lEach of thetabs are provided with holes 20a, b, c, d for receiving pins 22a, b, c,d associated with platform 12.

Platform 12 consists of a fiat plate of rigid material having downwardlyextending guide pins 22a, b, c, d secured thereto at positionscorresponding to the holes 20 provided in tabs 18. As shown,particularly in FIG- URE 3, the guide pins 22 are somewhat smaller thanthe holes 20 so that the platform 12 can be lifted slightly at eachside, that is to say, tilted at an angle about one side of the rectangleand defined by the tabs 18 without causing any binding of guide pins 22in -holes 20.

The platform 12 is provided with means on its lower surface for forminga cam track having varying levels. The cam track includes four cams 24a,b, c, d, each of which is provided with a lower surface including ramps26a, b separated by a flat 28, the length of which defines the durationof maximum tilt of the platform. As shown, each of the cams 24 has thesame shape and is screwed tothe underneath of the platform 12 to definea cam track in the form of a closed circular loop. The track preferablylies at the midposition between the guide pins 22a, b, c, d, and theplatform with each cam opposed to a set of guide pins at the oppositeside of the platform. In this way, raising of cam 24a, for'example,causes the platform to pivot upwardly about a line joining tabs 18b, 18eand the associated pins 22b, 22eI as though the platform were hinged onthat line. Similarly, the platform is pivoted about a line joining theadjacent tabs and pins by raising the opposite cam.

Means are provided for sequentially engaging and raising cams 24a, b, c,d and consist of a rotor arm 30 driven by suitable gear motor 32 havingrotating output shaft 34 to which the arm 30 is secured by a set screw36. The gear motor 32 is supported by a shelf 38 which is secured to theside walls of the housing 10 in a plane parallel to and below platform12. A suitable electric cord 40, switch 42 and plug 44 are provided forsupplying electric power to the gear motor.

Shelf 38 also supports a rigid circular disc 50 having a planar uppersurface 52 which extends to the inner perimeter of the cam track. Rotorarm 30 carries an outer antifriction ball bearing 54 having an innerring S6 secured to the rotor arm and an outer ring S8 resting on theperiphery of surface 52 of the disc 50. As the rotor arm is driven aboutits axis of support, bearing 54 rolls about the periphery of disc 50 andis supported thereon. A cam drive bearing 60 is carried by the outer endof rotor arm 30 at a position spaced outwardly from the support bearing54 and is preferably of a ball bearing, antifriction type having aninner ring 62 engaged between a spacer 64 and a suitable means 66 forsecuring the bearings 54 and 60 together onto the end of the rotor arm30'.

The outer ring 68 of the drive bearing lies at the level of surface 52and cams 24a, b, c, d and travels along the path of the cam track.

The operation of the above described apparatus is particularly simpleand effective. As the output shaft 34 of gear motor 32 rotates, itdrives the rotor arm 30 in a sweeping arc so that the outer end of therotor arm travels in a circular path. Bearing 54 rolls on the peripheryof the disc 50 on surface 52 to support the outer end of tle rotor armin a substantially horizontal plane. As the cam drive bearing 60 isdriven about the cam track by motor 32 and arm 30, it sequentiallyengages and lifts each of the cams in turn, the lift force beingsupplied from the discv 50, through bearing 54. The amount of lift isdetermined by the height of the cam 24 and the duration of lift isdetermined principally by the length of the flat 28. After engaging acam and lifting the cam and platform, the cam bearing rolls off thereturn ramp 26h to smoothly return the platform to its rest position onthe tabs 18. The motion of the platform is characterized by a four wayrocking motion due to the platform being successively pivoted apredetermined small angle about axes lying in a common plane defined bythe lines joining tabs 18a, b, c, d. The axes transversely intersecteach other so that each agitation step is successively directed inopposition to the prior step. One suitable agitation cycle results fromusing a rotor arm speed of about 6 revolutions per minute.

Thus, there has been provided a particularly eective tray rockingapparatus which is positively driven and which produces a four wayrocking motion from simple rotary motion. By using a central axis drive,the amount of lift provided increases or decreases as the tray size isincreased or decreased. The photographic tray 14 may be positioned asshown in FIGURE l so that it is rocked from its sides but it is obviousthat the tray can be turned 45 degrees so that the rocking motion takesplace from its corners. To those skilled in the art to which theinvention relates, many modifications and adaptations of the inventionwill suggest themselves. For example, the pivot lines between tabs 18can be arranged in a rectangular pattern, as shown, or can be arrangedin other configurations as on a square or other plan. Accordingly, it isto be understood that the descriptions and disclosures herein are not tobe taken in a limiting sense but are given as an illustration of theinvention, the scope of which is to be determined by the followingclaims.

I claim:

1. In apparatus for rocking a tray to agitate a photo- 4 f graphicsolution contained therein, a platform for carrying the tray, means forsupporting the platform in a substantially horizontal position whilepermitting the platform to be pivoted about intersecting axes lying in acornmon plane, means forming cams carried `by the lower surface of saidplatform, said cams having varying levels, and means mounted beneath theplatform for periodically engaging the cams to sequentially lift theplatform about successive ones of said intersecting axes.

2. Apparatus as in claim 1 wherein said means for periodically engagingthe cams includes a rotor arm, means mounting said rotor arm forrotation in a plane lying below and parallel to the platform, said rotorarm carrying a cam driver thereon for sequentially engaging each of saidcams.

3. Apparatus as in claim 2 wherein said means mounting said rotor armincludes a bearing mounted intermediate the length of said rotor arm anda disc supported in a plane lying below and parallel to said platform.

4. Apparatus as in claim 3 wherein said cam driver is' an antifrictionbearing having a cylindrical surface adapted to engage and roll oversaid cam.

5. Apparatus as in claim 2 wherein said means for pe-v riodicallyengaging the cams includes an electric motor including means forproviding a rotating output shaft, said shaft being transverselyconnected to said rotor arm.

6. Apparatus as in claim 1 wherein said means for supporting theplatform includes horizontally extending tabs positioned at the cornersof a rectangle, each of said tabs having a hole therein, and furtherincluding guide means carried by the lower surface of said platform andpositioned to align with said holes, said guide means and holes freelyengaging each other so that the platform is free to be pivoted aboutaxes defined by the sides of said rectangle. References Cited UNITEDSTATES PATENTS 1,871,374 8/1932 John 259-72 2,877,700 3/ 1959 Keller95-99 XR 2,976,792 3/ 1961 Chambers 95--99 NORTON ANSHER, PrimaryExaminer FRED L. BRAUN, Assistant Examiner U.S. Cl. X.R. 134-118; 259-72

